Description of Cyphoderia ampulla

Testate amoeba, shell is colourless or yellow, retort-shaped and circular in transverse section. It is composed of circular or oval, flattened, siliceous test plates, which are arranged in diagonal rows on an organic matrix so that they either lie close or touch, but do not overlap. The aperture is circular and surrounded by a row of shell plates. Length of test 61-190 microns, diameter of test 33-72 microns, diameter of aperture 10-22 microns, diameter of shell plates 1.5-2.5 microns.